The present invention relates generally to apparatus for mounting and controlling transducers employed with sonar sensing devices. More particularly, the present invention is directed to a system, ideally for use by fishermen, which extends a sonar depth finder transducer away from the boat and enables it to probe underwater areas other than those immediately beneath or proximate the boat.
Sonar techniques for scanning underwater obstacles and for measuring depth have long been in use. Various forms of sonar operated transducers are readily available for sport fishermen, and they function as depth finders and fish locators. The sonar unit is electrically powered, and it is interconnected with a remote sonar transducer through a conventional cable. Transducers are well known to fishermen, and they usually are either associated mechanically with the hull of the boat, or they are mounted generally vertically and project away from the side of the boat by conventional usually vertical mounting brackets or the like. It is usually the procedure to scan that area immediately below the boat, and most fishing sonar systems for fisherman are limited by this handicap.
A wide variety of prior art patents exist in the sonar arts. U.S. Pat. No. 3,113,287 discloses a typical fisherman's transducer adapted to be mounted directly in the boat hull. A similar through-hull design for reception of a spherical transducer is disclosed in King patent 3,753,219, issued Aug. 14, 1973. The mounting system for a spherical transducer is also shown in U.S. Pat. No. 3,716,827, issued Feb. 13, 1973.
An outboard transducer assembly for sonar seen in U.S. Pat. No. 2,646,950, issued July 28, 1953. Joseph 3,740,706 discloses a system for mounting a marine hydrophone transducer which allows for non-destructive break-a-way when the probe strikes an underwater obstacle. Mayes patent 2,837,727 also discloses a "vertical" probe mounting system, and means are disclosed for rotating the transducer relative to the mounting system to scan an underwater area proximate the boat. The transom transducer mounting bracket of U.S. Pat. No. 3,729,162 disclosed by Salvato also provides a system wherein an unwanted encounter with an underwater obstacle enables the transducer to be swiveled away out of harms way. The disclosures of U.S. Pat. Nos. 3,714,619; 3,521,225; 2,671,206, and 3,454,923 are also of limited relevance to my invention.
The most relevant prior art known to me is seen in U.S. Pat. Nos. 3,989,216 and 4,152,690 issued to Veatch. The '216 patent discloses a vertical side mounted system for operatively interconnecting a sonar transducer proximate a boat for purposes of swiveling and and scanning beneath and around the boat. Patent 4,152,690 discloses a system wherein the sonar transducer may be operatively associated beneath the water with a trolling motor, and a cable system is provided for pivoting it in a desired scanning direction.
I have found through experimentation and experience that it is usually desirable to remotely position the transducer away from the fishing boat. Also, it is important to provide a pivoting system wherein the transducer can be moved to scan a remote area, more useful results are obtained with a remote system spacing the transducer away from the boat. I have found it desirable to provide a remote system which spaces the depth finder (i.e. or sonar fish locating) transducer away from the side of the boat toward an area or region which may be inaccessible to the boat. I have also found it desirable to "float" the transducer near the top of the water, and in combination with a compensating boom assembly it may be positioned in a variety of "hard to reach" positions which would otherwise be inaccessible by the sonar equipped fisherman.